Relay



' Dec. 19,1922.

J. c. LI NDNER. RELAY.

EILED APR. 4 l9l8.

V, Patented Dec. iaieaa p p I srarq: ars

Jenn o. Lrnnnnn, or,nooHEsTE3, NEW YORK, ASSIGNOB 'ro GENERAL RAILWAY' SIGNAL COMPANY, or earns, nnw roan, ACORPORATION on NEW YORK.

RELAY. 7

- Application'fil'ed April 4, 1918. Serial No. 226,711.

To aZZ whom/it may canoe rm. of the signaling system depends upon the Be it known that 1, JOHN C. LINDNER, a contacts separating and breaking the circuit 55 citizen of the United States, and resident of when the relay is de-energized/ 1 the city of Rochester, in the county of Mon- On account of these objections tothe use roe and State otlNew York, have invented of metal to metal contacts,-it has been proa new and useful Relay, of which the followposed to make either one or both of the coning is aspecification. a tacts of I graphite, carbon or some other 60 This invention relatesito'improvements in highly refractory material. In the'contact the contacts of relays ofthe type commonly construction for relays quite commonly used 10 used in electric signaling systenisfor railat the present time, a'button of carbon or ways. graphite is made thefixed contact, while the In railway signaling systems, it is found movable contact is made of some highly con- 65 in practice that the availableenergy for opductive metal, such as silver. Such aconcrating the relays is comparatively small, esstruction is found to obviate the difiiculties l5 pecially in the case of track circuits. On 210- attendant with the use of metal to metal concount of thislimitationin operating energy, tacts,but introduces the otherdifiiculty of a. relay, made'so that it will operatesatisfachighand variable contact resistance. Prac- 7 torily under these conditions," is capable of tical experiencehas demonstrated that there i exertingonly a comparatively small presisgreat'diflicultyin obtaining withthis consure between its contracts, and likewise a struction low contact resistance, or a contact comparatively small force tending to separresistance which will remain constant, it

ate the contacts. It, is highly desirable, having been found lmt'fm $01118 refisflm the however, that the contact resistance be as contacting surfaces of the carbon or metal J low'as possible, on-account of the length of are in some waycaused totleteriorate and the circuits, the comparatively low voltage increase the contact resistance a fterthe re I avai'lable,and the number of relay contacts layh as been operated for a time. w p v oftenincluded in such circuits. The desired lVit-h the above consideration invi'ew, the 80 low contact resistance n ay-be obtained by primary object of this invention is-to prothe use otmetal to metal contacts, but in the vide'a contact construction for relays which practical use of relays, it has been found will possess the desirable requisite otlow v f that such metal to metal contacts have sericontact resistance, but which will a't the same ious disadvantages. In the first place, the time prevent the deterioration or tusingot 85 circuits opened and closed by the relay conthe contacts. 5 i I acts are often highly inductive and upon A furtherobject of the invention is to obseparation of the contacts byt-he deenergizatain this'end by a simple, inexpensive and tion of the relay, arcs are generally drawn. reliable construction, which will not easily I This continual arcing'between the contacts getout of adjustment. 'I 90 in time results inpitting and roughening the Other objects and advantages will appear contact sin-faces to such an extent that the as the description progresses andthe novel L0 contact resistance is materially increased, features of the invention will be particu and frequent rei'icwal of these contacts is larly'pointedout in the appended CliLlD'lS. required. Also, it has been found in some In describing the invention in detail, ret- 5 cases that the metal to-metal contacts have erence will be made tothe accompanying I z-rctually -been fusedtogether, due to excesdrawin s, in which isillustrated a preferred sive currents, occasionedby lightning or physicad embodiment of this invention, and other heavy current discharges through the in which like reference characte'rsrefer to relay. on account of the comparatively corresponding partsthroughout the several 1.00

small force available forseparating the'conviews, and in which! l tacts, only a slight lusing or sticking; to- Fig. 1-is'a'side elevation of a preferred nether of the contacts is sufiicient to prevent type of relayembodylng my 1nvent1on;" I

"them from separating and breakingthe c1r- 1 Fig. 2 1s a front elevation of the relay cuit." This fusing of the-contactstogether is shown in Fig. 1;

highly objecti0nable,-since the entire safety Fig. 3 is an enlarged sectional view taken.

substantially on the line 3--3 in .Fig. viewed in the direction indicated by the arrow a. and showing in detail the contact construction embodying this invention, the parts being in the deenergized or open position;

Fig. 4: is a fragmentary section similar to Fig. 3 showing the parts in the picked up or closed position; and

Fig. 5 is a bottom View of the contact post shown in Figs. 3 and 4:.

Referring to Figs. 1 and 2 of the drawing, I have illustrated a preferred form of my invention applied to a well-known type of relay.

This relay comprises the usual pair of relay coils 11 with a back strap 3 and cores a which are fastened to a coil support 5, secured to a top plate 6 of the relay casing. This casing consists of a base plate 7, the carrying or top plate 6, and glass walls or sides 8. .The sides 8 are seated within flanges on the top plate 6 and base plate 7, which are held together by screws 9; and with gaskets between the sides 8 and the plates 6 and 7, this housing "forms a dampproof chamber for the working parts of the relay. The relay armature 10 is pivotally secured to the lugs 11 integral with the coil sup v, port 5; and carried by but insulated from the armature 10 are contact fingers 12. These contact fingers 12 are bent slightly down ward at one end and carry at that end a pair of resilient contact pieces 13 and 14: which are adapted to cooperate with fixed back contact posts 13 and front. contact posts F, respectively -The opposite ends of the contact fingers 12 are electrically connected by flexible connections 15 to binding posts A, which are secured to and insulated from the top plate 6.

My invention relates more particularly to the construction of the front contact post F which is secured to and insulated from the top plate 6. This front contact post F comprises a spindle 16 which is screw threaded tor a part of its length; and which has an enlarged head or holder 17 at its lower end. The base portion of the holder 1 is squared andv fits without turning in a slot 18 cut in a block 19 of suitable insulating material whicl'i extends across the under side of the top plate 6. The spindle 16 forms in effect a binding post and. is insulated from the top plate 6 in the usual manner, as shown in Fig.3, and is clamped in position on the top plate 6' by nuts which are screwed down on. the threaded portion of the spindle 16, as shown in Fig. 3. The holder 17 has a cylindrical cavity formed therein to receive a button 20 of carbon, graphite, or other retrac 'tory material. The button 20 .is pressed tightly into this cavity inthe holder 1T,-and the edges of the holder are spun over to hold the button 20 rigidly in position. Between the button 20 and. the bottom of thel cavity i any convenient manner as for instance by rivets, as shown 1n Flgs. 2 and 3. This strip 22 1s shaped to fit snugly along the contour of the holder 17 and the button 20, and e):- tends a short distance below the under face of the carbon button 20.

- The contact piece 1&- on the contact linger 12-is positioned at an oblique angle to the axis of contact post F as shown in Fig. 1, so that when the contact finger 12 is raised, the contact 1% will first make contact with the carbon button 20 and then, due to the pressure exerted on thecontact finger, will fiatten out and slide lengthwise along the con tacting surface of the button 20 until it touches the metallic strip 22.

Operati0m-l 7hen the relay coils 11 are energized and the armature 10 ispiclred up, the contact fingers 12 carried thereby will be raised to position wherein the resilient contact pieces 14; make contact with their cooperating front contact posts F. As explained herenibefore, the parts are so proportioned and shaped that the contact pieces it will first make contact with the carbon button 20, then with theresilient metallic strip 22. ()n the contrary, when the relay is deenergized, and the contact finger l2 moves downward, the first eflect is to relax the pressure upon the contact piece 14, so that this contact piece slides lengthwise outof contact with the metallic strip 22, and then finally the contact piece 14 separates from the carbon button 20 and-breaks the circuit. a

By reason of the construction embodying this invention upon energization of the relay, electrical contact is made first between metal and a refractory material, and then between two metals of low resistance. Since the circuit established between metal and carbon, any spark or arc which might occur "would not cause fusing, and by the time the is easyto adjust, and is not likely to work out of adjustment. The metallic contacting pieces 14 and 22 may be readilyreplaced at a small expense. M

Although I have particularly described the construction of one physical embodiment of my invention and explained the operation and principle thereof, nevertheless, I

desire to have it understood that the form selected is merely illustrative and does not exhaust the possible physical embodiments of the idea of means underlying my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In a relay, the combination with a pivoted armature and coils for actuating said armature, of a contact post comprising a fixed carbon contact and a resilient metallic contact, a contact finger carried by said such engagement to move into contact with the resilient contact without breaking contact with the carbon contact.

2. In a relay, the combination with the pivoted armature and coils for attracting said armature, of a contact post provided with a fixed carbon contact and a contiguous resilient metallic contact, and a resilient metallic contact piece actuated by thearmature and disposed at an angle with respect to its direction of movement, said contact piece initially engaging the carbon contact as the armature is attracted and being flexed by such engagement to move into contact with the-metallic'contact without breaking contact with the carbon contact.

3; In a relay, the combination witha pivoted armature and coils for actuating said armature, of a fixed contact post, comprising an elongated spindle which is screw threaded atone end to form a binding post and formed at its other end with an enlarged head having a cylindrical cavity therein, a contact button of refractory ma: terial rigidly held in said cavity, a resilient metallic contact strip of relatively low resistance secured, to said holder and extend ing below the contacting surface of said button, and a contact finger carried by said armature and having a resilient I contact piece secured to one end which is normally disposed in angular relation to the contacting face of said button, said contact piece engaging initially with said but- I ton and being flexed by such engagement to &

move into contact with said metallic con tact strip.

4. A relay comprising a contact post hav piece disposed at an angle to thedirection of movement of said finger, said contact piece initially engaging the refractory fixed contact as the finger is moved to its attracted position and being flexed by such engagement to contact at its end against the metallic fixed contact.

5. A relay comprising a vertically movable contact finger carrying a resilient contact piece, and a contact post for cooperating with said contact piece and provided with a fixed contact of refractory material and a metallic contact of-relatively low resistance with horizontally and vertically dispose-d contact surfaces respectively adjacent to each other in the plane of movement of said contact finger, said contact piece being inclined with respect to said contact surfaces of the fixed contacts and being initially engaged with the refractory contact by the upward movement of the contact finger and being projected by such engagement into endwise contact with said metallic contact.

6. A contact post for relays comprising an elongated metallic spindle, a button of refractory material attached to said spindle, and a resilient metallic contact strip of relatively low resistance attached to said spindle and partly projecting beyond the outer face of said button.

7. In a contact construction for relays of the tractive type provided with a vertically movable contact finger and a fixed contact post cooperating therewith, a resilient contact piece carried by said contact finger, said post having a recess holding a carbon button and being provided with a resilient metallic contact strip of relatively low resistance partly projecting beyond the outer face of said button, the contact piece of said finger being inclined with respect to the surface of said carbon button, said contact piece engaging initially with the car- 'bon button and being flexed by such en- JOHN C. LINDNER. 

